Hot Rods Clutch pressure plate issues

OK, let me put this another way. If the disc was too thick the fingers (in this case the Belleville spring) will go too low when the pressure plate is tightened to the flywheel. The pedal is depressed, contact is made and the clutch is disengaged, but with some difficulty. Was the “oil canning” caused by the tips of the Belleville spring catching on the throw out bearing?
The OP posted a picture of notches worn into the bell housing by the fork. Only excessive movement of the fork could cause that. A measurement of the disc may possibly have provided an answer.

 

Wanderlust- that's what I'm thinking too

NoelC- I agree. Not a real smoking gun that I was hoping for either. I was really hoping that he would look at one or all of my parts and give me a very clear explanation as to why they don't work together. He said the pressure plate and flywheel are for a much later year. It's possible then that the clutch disc that was packaged with this kit was too thick. Since I did not have an original clutch disc to compare it to, the three clutches that I had to look at and put my dial Caliper on we're all the same thickness. He did mention that there were different late model Bell housings which would use different shaped clutch forks.

Pist-n-broke- that's what it sounds like to me. Just parts that were obsolete or eliminated and replaced with this part number for the inline 6. Somewhere along the way it was substituted and somebody got it wrong apparently.

Fordors- I purchased two brand new clutch kits from two different manufacturers and had an old clutch disc that my brother had taken off of a 292 inline. All three of them had the same thickness with the dial calipers. The used one of course was slightly thinner but not much. I completely agree with you that the components in that kit should work. A pressure plate simply bolts to a flat decked surface of the flywheel. The clutch disc is in between these two parts. When the pressure plate cover gets torqued to the flywheel, the diaphragm springs should work as designed. As it was with this particular combination, I had very little stiff pedal travel, and then it went past center. That's what the transmission guy explained it as. The popping or the oil canning is the diaphragm springs going past center. As you guys already saw, my diaphragm springs almost started out at center. The only thing I could think that would make that happen is a thick clutch disc or the wrong flywheel. If there was a fly wheel that had the pressure plate mounting surface further away than the clutch disc contact surface then it would give it more travel for the diaphragm springs. But that seems pretty silly. I honestly do not know why this did not work unless the clutch discs were supposed to be much thinner then the discs that were included in the kit.

Pist-n-broke- I think you're right.

Nailhead Jason- that's strange! Similar problem however if you ordered a clutch kit for a V8, based on my experience here, you should have received the correct clutch kit. Now I'm beginning to wonder what the hell is this low cone clutch kit designed for? It seems that no one has experience with it and that the tall cone is the answer for Chevrolet. I'm very curious now which years and models the low cone was used. I'm glad to hear that other clutch companies have it figured out. Maybe it's just LUK.

Fordors- I agree with your description and I believe that's how it works. In earlier photographs, you can see it just how flat the diaphragm springs were when the pressure plate was torqued to the flywheel.
The wear notches in the bellhousing were caused by the previous owner of the Bell housing. I purchased it used at a swap meet. Once I put this engine and trans back in the truck and hook up my linkage, I will see just how for the clutch fork travels.

This week has been busy for me but I'm hoping to have the motor back in Sunday. I will post updates when they are relevant and once the truck is moving under its own power I will post a video on YouTube and put the link on here so that this thread will have a full conclusion.
Thanks!

 

Sounds like this problem is put to rest and you can move on to the next issue. Let's hope it's much smaller and easier to cure.

 

BAM!

I think you and your driveline guru have got this job properly sorted. I'm guessing this new kit came with a shorter T.O. bearing as well.

You probably don't want to do any more experimenting at this point. But if I were you (and at this point I'm glad I'm not!) I'd want to mount your latest, high-cone disk and pressure plate to the old flywheel and see if everything moves smoothly enough to disengage the disk without any oil-canning. And I'd expect it to work just as well with your new flywheel.

But it's kind of a shame that you didn't have a flywheel with the recessed wear surface to try out. I'd guess that your low cone P.P. and disk would have worked smoothly on this combination as well. As a matter of fact I probably would have bolted the low-cone P.P. to the old flat faced flywheel with NO disk installed just to see what kind of results it gave.

The low-cone kit may have worked OK with a recessed flywheel, if you already had one in your "inventory". But in this case you should be better off using the flywheel and clutch kit recommended by your new friend at the driveline shop. They look to be heaver duty parts and I expect he'll be more willing to advise you if you have any more questions.

When you get everything on the road and rolling again you might want to share this fellow's name here and give his business' name and location as well. If he has any interest in old cars and trucks he might decide to join the HAMB and drum up a bit of business from members in your part of the country.

 

Bottom line is LUK and NAPA have no idea what goes with what on these older engines. I have been through 3 clutches in the last week that don't fit for a 1954 truck 235 with a saginaw from NAPA including one that after having called the LUK techline I was assured it would fit. I am having my original rebuilt which is what I should have done from the start.

 

No, bottom line is today’s after market needs to stop reinventing the wheel in an attempt to cut cost. Just copy what works.

 

The first picture is a flat finger diaphragm as used in GM six cylinder, and four cylinder Chevy II’s also. The bent finger was used with most (if not all) V8’s. There has never (at least since the ‘50’s) been a stepped flywheel on a GM engine, the pp mounts on the same level as the disc surface.
The LUK flywheel you bought is a cast iron knock-off of the Chevrolet L-88 16 pound, nodular iron flywheel, it was introduced in 1969 or ‘70 and is not from any late model application contrary to what you were told. Think about it, since the eighties (was it ‘86 when they changed?) Chevy’s have had one piece rear main seals, that LUK ‘wheel won’t bolt up to any late Chevy engine.
Either you had a thick disc or the wrong pressure plate, what was the thickness of the LUK disc?

 

ClayMart- Thanks, yes, the new kit has the shortest throw out bearing. I will ask the fellow if he minds me sharing his info on this forum. I took a lot of awesome pics of his shop. He's big time into the oldies, just like the HAMB. Nothing newer than 70's in his shop, and its large!

K13- Sorry to hear of your problems. At least you found a solution far before I did. Good luck!

Johnny Gee- Agreed

Fordors- Thanks for sharing those excellent illustrations! The caliper on the clutch disc was 0.328 (For people joining late, I put my dial calipers on several parts on page two of this thread)
I thought the disc was too thick as well. Either that or wrong pressure plate. Do you know for sure what the thickness of the clutch disc should be for an inline 6?

Thanks!

 

Well I guess no news is good news!

Does this mean it's shiftin' smoother than a gravy sammidge?